Advanced bike frame design

Abstract

An advanced frame design primarily for mountain bikes that utilizes an advanced construction of lightweight tubes to create bicycle framework of greater strength without added weight. The frame design utilizes pairs of thin tubes arranged within the bike frame for increased strength and flexibility. The top tube and down tubes are of double tube construction in the invention. Bridgework tubes are smaller tubes that are used to connect portions of the various doubled tubes to one another to provide a secondary support structure for the frame.

I claim: 
     
       1. An improved bicycle framework comprising: a seat post tube having two ends, one of said ends having a bottom bracket and the other of said ends adapted to be in connection with a seat; a head set tube having a top portion adapted to be in connection with a pair of handle bars, a pair of top tubes generally parallel to one another; said top tubes in connection with said top portion of said head set tube and said seat post tube; a first pair of down tubes generally parallel to one another and having one end of each of said first pair of down tubes in connection with said pair of top tubes at a point on said top tubes about midway between said seat post and said head set, the other end of said first pair of down tubes in connection with said bottom bracket; a pair of reinforcing tubes, each of said reinforcing tubes connected to one of said first pair of down tubes and said seat tube. 
     
     
       2. The apparatus of claim 1 having drop out portions and having a second pair of down tubes having one end connected to said head set and extending beyond said seat post to connect with said drop out portions, each of said second pair of down tubes connected to one of said first pair of down tubes at a point of intersection and having a straight bridgework member connected to each of said second pair of down tubes at said point of intersection. 
     
     
       3. The apparatus of claim 2 having a pair of chain stay tubes extending from said second pair of down tubes and located above said bottom bracket. 
     
     
       4. The apparatus of claim 2 wherein said top tubes and said down tubes are made of carbon fiber material. 
     
     
       5. The apparatus of claim 2 wherein said top tubes and said down tubes are made of titanium material. 
     
     
       6. The apparatus of claim 3 wherein said top tubes and said down tubes are made of carbon fiber material. 
     
     
       7. The apparatus of claim 3 wherein said top tubes and said down tubes made of titanium material.